Central Incisor Teeth Research Articles

Diagnosis and endodontic treatment of odontogenic cutaneous sinus tracts: A report of two cases

Introduction: The odontogenic cutaneous sinus tract (OCST), caused by pulp necrosis, creates connections between pathological spaces and anatomical structures. Extraoral manifestations pose diagnostic challenges leading to inappropriate treatments such as multiple surgery and antibiotic therapies. Effective management requires the treatment of dental pathology through endodontic therapy or extraction. This paper presents two cases of OCST and emphasizes the importance of accurate diagnosis and successful non-surgical endodontic treatment. Observations: Case report 1: A 23-year-old male patient referred by his dermatologist with a cutaneous sinus tract on his chin that had appeared five years ago. During this period, he reported spontaneous pain and pus discharge from the chin area. The examination revealed a periapical lesion associated with tooth number 31. Cone beam computed tomography (CBCT) revealed the existence of a localized perforation on the buccal alveolar table and a second root canal of the tooth. After six months of follow-up, the cutaneous sinus tract was significantly improved by the appropriate endodontic treatment. Case report 2: A 36-year-old female patient was referred by her dentist to examine a chin lesion that had appeared a month ago. In clinical examination and radiographic assessment, periapical lesion associated with two mandibular central incisor teeth #41 and #31 was observed. After identifying the source of infection, endodontic treatment was carried out, and a good improvement in fistula was observed after one month. Conclusions: The correct diagnosis and treatment of OCST are important for healing. CBCT aids to identify odontogenic origin of the sinus tract through the detection of apical periodontitis and bone lesion. Root canal therapy is the treatment of choice for these cases and should always be attempted first. Monitoring the patients is necessary until complete healing of the disease.

Treatment of Dento-alveolar Traumatic Injuries in a Child with Autism Spectrum Disorder (ASD)

This case report details the multidisciplinary management and follow-up of a 9-year-old boy diagnosed with autism spectrum disorder (ASD). He presented with severe intrusion injuries after a fall to his permanent maxillary central and lateral incisor teeth. The patient was initially seen in the emergency department by the maxillofacial team. Owing to the complexity of the dento-alveolar injury, it was felt that a multidisciplinary approach would improve patient outcomes. In theatre, both maxillofacial and paediatric dental teams managed the acute trauma. The paediatric dental team continued to review and follow-up with the child. A multidisciplinary team is ideal for managing paediatric patients with severe dental trauma and complex behavioural needs. This approach ensures the best care for patients and favourable outcomes. CPD/Clinical Relevance: Multidisciplinary management is important in paediatric dento-alveolar trauma.

CT-Assisted Management with Biodentine Obturation and Aesthetic Rehabilitation of a Geminated Maxillary Central Incisor with Mid-Root Fracture: A Rare Case Report

Gemination, a rare aberration in tooth development, results from the incomplete division of one tooth germ into two. In this case report, a true geminated permanent maxillary central incisor tooth with a horizontal mid-root fracture is successfully treated by non-surgical endodontic treatment. To elucidate the intricate root canal anatomy of this rare geminated incisor, we employed computed tomography imaging technology, enhancing our understanding of this complex case. Utilizing biodentine for obturation proved pivotal, as its capacity to accelerate reparative dentin formation facilitated prompt healing, particularly beneficial in fracture cases. This was followed by aesthetic rehabilitation to achieve a pleasing mesio-distal dimension for both the central incisors using a zirconia-reinforced porcelain crowns. Keywords: Computed Tomography (CT), Gemination, Horizontal root fracture, Biodentine Obturation

A Comparative Evaluation of the Effect of Different Endodontic Irrigating Solutions on Microhardness of Root Canal Dentin: An in vitro Study.

During endodontic therapy, irrigation solutions applied in the root canal may affect the physicochemical properties of the dentinal wall, thereby changing its microhardness. This may adversely affect the sealing ability and adhesion of dental materials. Therefore, many studies have focused on the search for an ideal root canal irrigant that has a minimal effect on dentinal microhardness. This in vitro study was conducted to determine the changes in dentin microhardness after root canal irrigation with different endodontic irrigants. Ninety-five freshly extracted maxillary central incisor teeth with straight single canals were selected. These teeth were sectioned transversely at the level of the cementoenamel junction. The working length of each tooth was determined, and canal space was prepared by the HyFlex CM rotary file system. During instrumentation, normal saline was used for irrigation. Then, teeth were split longitudinally into two segments. According to the irrigating solution employed, samples were divided into five groups (n=19): normal saline (Group A), 3% sodium hypochlorite (Group B), 2% chlorhexidine (Group C), 5% calcium hypochlorite (Group D), and 0.2% nanochitosan (Group E).3 mL of the corresponding irrigating solution was administered for total15 minutes in each prepared sample. The Vickers micro-hardness tester was then used to assess micro-hardness. The data was analyzed using one-way analysis of variance (ANOVA). All tested irrigating solutions decreased the dentinal microhardness. Samples irrigated with 5% calcium hypochlorite demonstrated dentinal microhardness of 42.43±1.62, which is the lowest among all the tested groups, followed by nano chitosan, sodium hypochlorite, and chlorhexidine. Samples treated with control group (saline) demonstrated the maximum microhardness of dentin in the present study. Within the limitations of this research, it can be concluded that the tested novel irrigating solutions, 5% calcium hypochlorite and 0.2% nanochitosan, were more detrimental to radicular dentin microhardness when compared with conventional endodontic irrigants.

Quantitative statistical evaluation of maxillary and mandibular incisor root canal morphology in Saudi patients

Abstract Introduction: Clinical practice demands understanding the complexity of the root canal system to achieve desired treatment goals. The statistically detailed morphology of the tooth and root canal morphology is very important to know. Therefore, the present study aims to investigate the statistical analysis of root canal morphology and morphological variations of maxillary and mandibular incisor teeth using cone-beam computed tomography (CBCT) in Saudi patients attending King Saud University Dental Hospital. Materials and Methods: CBCT images of 480 patients were selected. Number of roots and root canal configuration were identified and categorized according to Vertucci’s classification. Tooth length, distance from cementoenamel junction (CEJ) to the area of canal division, and width of the canal at the area of division were also evaluated. Bilateral symmetry and association between gender and age with the different variables were investigated. Data were analyzed using Chi-square, multiple linear regression, and McNemar’s tests. Results: A total of 3412 teeth were evaluated. All maxillary teeth had one root with Type I canal configuration. For mandibular teeth, all exhibited one root with the majority having Type I canal configuration in central (71.2%) and lateral (75%) incisor teeth. There was a statistically significant association between number of canals and age in mandibular incisor teeth observed only in females (P < 0.001), while no association was observed between canal configuration and gender (P = 0.900 and P = 0.721, respectively). Multiple regression analyses showed that age and gender significantly explain the difference of the variance in tooth length (P < 0.001). Moreover, bilateral symmetry was observed in 98.1% of mandibular central and 97.6% of lateral incisor teeth with no statistically significant association (P = 1 and P = 0.058, respectively). Conclusion: All maxillary and most mandibular incisor teeth present with one root and Type I canal configuration. In general, males have longer teeth than females, with a significant decrease in length with each year increase in age. Mandibular lateral incisor teeth exhibited the highest mean distance from CEJ to point of canal separation and highest mean width in the area of canal division.

Effect of hydrogen peroxide versus charcoal-based whitening mouthwashes on color, surface roughness, and color stability of enamel

BackgroundPatients tend to favor the whitening mouthwashes as they are easily applied and affordable. This study aimed to evaluate the effect of hydrogen peroxide versus charcoal-based whitening mouthwashes on color, surface roughness, and color stability of enamel. In the current study, the whitening mouthwashes used have the ability to stop future stains due to their white seal technology.MethodsA total of 21 permanent central incisor teeth extracted for periodontal reasons were used in the present study. Teeth roots were sectioned and crowns were mounted in self-cured acrylic resin blocks. The specimens were randomly divided into three groups (n = 7) according to the tested whitening mouthwash: Control group ‟ DW” (Distilled water), ‟OW” group: Peroxide-based mouthwash (Colgate Optic White) and ‟CP” group: Charcoal-based mouthwash (Colgate® Plax Charcoal). Regarding ‟OW” and ‟CP” groups, the specimens were immersed in 20 ml of the tested mouthwash in each corresponding group for 1 min twice daily (morning and evening) for a total of 12 uninterrupted weeks. Color change was assessed using VITA Easyshade spectrophotometer and surface roughness (Ra) was measured using a white light interferometer. The specimens were stained using black tea solution and color was measured after 24 h of immersion for assessment of color stability.ResultsColor change results revealed that both whitening mouthwashes were able to restore color comparable to the control group with no significant difference between them. Regarding surface roughness, the control group showed the highest mean Ra value, followed by ‟OW” group while ‟CP” group showed the lowest mean Ra value. While color stability after staining, the control group showed a significantly higher value than the ‟CP” and ‟OW” groups.ConclusionHydrogen peroxide and charcoal-based whitening mouthwashes improve the color of enamel with no adverse effect on the surface roughness. Both whitening mouthwashes were beneficial to maintain the color after staining and prevent future enamel stains.

Compressive Strength Comparison of Different Orthodontic Metal Bracket Systems

Rebonding of orthodontic brackets to new positions during treatment with fixed orthodontic appliances is a common practice and it is important not to cause plastic deformation during bracket removal. The aim of this study was to evaluate the resistance of various brackets to compression and assess their thresholds for plastic deformation. 5 different groups of metal brackets (BioQuick, Damon Q, Experience, Mini Diamond, Mini Sprint II) were bonded to 85 extracted human central incisor teeth utilizing the same adhesive system (Transbond XT). Compressive forces were applied via Weingart forceps in order to mimic clinical setting with the Shimadzu Universal tester. Kruskall-Wallis and Mann-Whitney U tests were used for comparing groups. Damon Q group exhibited the highest yield point value (549.35 N), the highest ultimate strength value (764.50 N) and the highest failure/debonding point value (721.89 N). The lowest yield point value (211.73 N), the lowest ultimate strength value (224.07 N) and the lowest failure/debonding point value (121.71 N) were found in the Mini Diamond group. The ultimate strength point values of Damon Q and Experience brackets were higher compared to Mini Diamond, BioQuick and Mini Sprint II brackets (p < 0.05). No statistically significant difference between Damon Q and Experience brackets in terms of yield strength and ultimate strength values (p > 0.05) were observed. Adhesive Remnant Index (ARI) score was 3 for all debonded samples. It may be concluded that Damon Q brackets were more resistant to plastic deformation than Mini Diamond, BioQuick and Mini Sprint II brackets (p < 0.05).

Age Estimation Using the Pulp-to-Tooth Area Ratio in an Indian Population Using Cone-Beam Computerised Tomography (CBCT): A Retrospective Study.

Age estimation, whether for living or deceased individuals, is crucial in forensic sciences. Traditionally, the pulp-to-tooth area ratio determined from periapical radiographs has been employed as a non-invasive method for estimating age. Cone-beam computed tomography (CBCT) represents a newer technique, providing three-dimensional images of teeth in living individuals. This study aims to estimate age using the pulp-to-tooth area ratio of four teeth (the permanent maxillary central incisor, lateral incisor, canine, and first premolar. The study included ninety subjects ranging in age from 18 to 70 years. This study concluded that the correlation between actual age and estimated age varied across different tooth types. There was a strong positive correlation between the maxillary right central incisor and maxillary right canine tooth, while the maxillary left canine tooth exhibited a slightly weaker but still positive correlation. This indicates that the maxillary right central incisor and maxillary right canine tooth are the most reliable for estimating age. Additionally, the study found that the linear regression results for estimating age based on the pulp-to-tooth area ratio, categorised by sex and each type of tooth, showed strong associations between age and the ratio for the maxillary left central incisor and maxillary left canine teeth in males, and for the maxillary left central incisor in females.

Quality of different obturation techniques to fill perforating internal root resorption: a micro-computed tomographic study

BackgroundThis study aimed to assess the quality of various obturation techniques to fill perforation caused by internal root resorption using Micro-computed Tomography.MethodsCone-beam computed tomography images of a maxillary central incisor tooth with perforating internal resorptive defect were used to create a 3D printed model of the affected tooth. The replicas were divided into four groups based on the obturation technique used. The techniques included Group 1: a polydimethylsiloxane-based sealer (GuttaFlow-2) with gutta-percha. Group 2: same as Group 1 except for using a pre-mixed Bioceramic-based sealer (NeoSEALER Flo). Group 3: the defect was filled entirely using the NeoSealer Flo Bioceramic-based sealer. Group 4: the samples were obturated using the warm vertical compaction technique with a resin-based sealer (ADSeal). The resin models were then scanned a micro-computed scanner to evaluate the percentage of voids in each group.ResultsThe results showed that NeoSEALER Flo groups had significantly the highest volume of voids while GuttaFlow-2 and warm vertical compaction groups had the lowest void volume.ConclusionsGuttaFlow-2 and warm vertical compaction techniques performed best in filling the internal resorptive defect.

Effect of the Height of a 3D-Printed Model on the Force Transmission and Thickness of Thermoformed Orthodontic Aligners.

This research aims to investigate the influence of model height employed in the deep drawing of orthodontic aligner sheets on force transmission and aligner thickness. Forty aligner sheets (Zendura FLX) were thermoformed over four models of varying heights (15, 20, 25, and 30 mm). Normal contact force generated on the facial surface of the upper right central incisor (Tooth 11) was measured using pressure-sensitive films. Aligner thickness around Tooth 11 was measured at five points. A digital caliper and a micro-computed tomography (µ-CT) were employed for thickness measurements. The normal contact force exhibited an uneven distribution across the facial surface of Tooth 11. Model 15 displayed the highest force (88.9 ± 23.2 N), while Model 30 exhibited the lowest (45.7 ± 15.8 N). The force distribution was more favorable for bodily movement with Model 15. Thickness measurements revealed substantial thinning of the aligner after thermoforming. This thinning was most pronounced at the incisal edge (50% of the original thickness) and least at the gingivo-facial part (85%). Additionally, there was a progressive reduction in aligner thickness with increasing model height, which was most significant on the facial tooth surfaces. We conclude that the thermoplastic aligner sheets undergo substantial thinning during the thermoforming process, which becomes more pronounced as the height of the model increases. As a result, there is a decrease in both overall and localized force transmission, which could lead to increased tipping by the aligner and a diminished ability to achieve bodily movement.

Effect of thermomechanical ageing on force transmission by orthodontic aligners made of different thermoformed materials: An experimental study.

Investigating the impact of thermal and mechanical loading on the force generation of orthodontic aligners made from various thermoplastic materials and different compositions. Five distinct materials were utilized including, three multi-layer (Zendura FLX, Zendura VIVA, CA Pro) and two single-layer (Zendura A and Duran). A total of 50 thermoformed aligners (n = 10) underwent a 48-hour ageing protocol, which involved mechanical loading resulting from a 0.2 mm facial malalignment of the upper right central incisor (Tooth 11) and thermal ageing through storage in warm distilled water at 37°C. The force exerted on Tooth 11 of a resin model was measured both before and after ageing using pressure-sensitive films and a biomechanical setup. Before ageing, pressure-sensitive films recorded normal contact forces ranging from 83.1 to 149.7 N, while the biomechanical setup measured resultant forces ranging from 0.1 to 0.5 N, with lingual forces exceeding facial forces. Multi-layer materials exhibited lower force magnitudes compared to single-layer materials. After ageing, a significant reduction in force was observed, with some materials experiencing up to a 50% decrease. Notably, multi-layer materials, especially Zendura VIVA, exhibited lower force decay. The force generated by aligners is influenced by both the aligner material and the direction of movement. Multi-layer materials exhibit superior performance compared to single-layer materials, primarily because of their lower initial force, which enhances patient comfort, and their capability to maintain consistent force application even after undergoing ageing.

Effect of various surface treatment methods on shear bond strength between acrylic denture teeth and thermoplastic nylon denture base

AbstractPurposeTo evaluate the effect of mechanical, chemical, and mechanical‐chemical surface treatment methods on shear bond strength between acrylic denture teeth and thermoplastic nylon denture base.Materials and MethodsMaxillary central incisor teeth were treated with five different surface treatment methods: mechanical (sandblasting, T‐shape diatoric holes), chemical (5% acetic acid solution, bonding agent), and mechanical‐chemical (sandblasting + bonding agent) were embedded in thermoplastic nylon denture base (n = 10). A universal testing machine with a crosshead speed of 0.5 mm per minute was used to test the shear bond strength. Data obtained were statistically evaluated using one‐way ANOVA and followed with Tukey post hoc test (α = 0.05)ResultsT‐shaped diatoric holes exhibited significantly higher shear bond strength among the surface treatment groups, followed by sandblasting + bonding agent, sandblasting, bonding agent, and the acetic acid group (p < 0.001)ConclusionT‐shaped diatoric holes as a mechanical surface treatment showed higher shear bond strength than other methods.

Evaluation of different color measurement methods for determining tooth color.

The purpose of this study is to develop software at a low cost that enables the detection of tooth colors by capturing photographs using various devices, and to compare its effectiveness with existing expensive methods. A total of 60 anterior central incisor teeth from 30 individuals were included in the study. The CIELAB values (L,a,b) of each tooth were measured using a spectrophotometer, which is considered the gold standard. Subsequently, photographs of the teeth were taken using four different smartphones (iPhone- Xiaomi) and one digital camera (Canon). These images were then subjected to image processing techniques and compared with measurements obtained through computer-based analysis in order to assess the correlation. Data with three or more groups, the Kruskal-Wallis H test was utilized, and multiple comparisons were conducted using the Dunn test. A significance level of p<0.05 was considered. Upon examining the results of multiple comparisons, a statistically significant difference was observed (p<0.001) between the DeltaE values obtained from the camera of the iPhone and those obtained from the Canon DSLR and Xiaomi cameras. The iPhone cameras yielded result values ranging from 2.68 to 2.90 for DeltaE. It is reported that color determination methods based on image processing of photographs taken with iPhone mobile phones could potentially gain an advantageous position in routine clinical practice, as compared to spectrophotometry.

Etiology and Demographic Distribution of Odontogenic Abscesses in the Maxillofacial Area in Patients Over 18 Years of Age: A Five-Year Retrospective Study.

Introduction Despite the constant development of medicine and the increasing accessibility to medical specialists, in the first quarter of the 21st century, odontogenic abscesses remain one of the leading causes of emergency hospitalization in maxillofacial surgery clinics. Because of the serious and lethal complications that this type of suppurative infection can lead to if not treated promptly, there is a need for constant updating of the knowledge of its origin, which is precisely what is addressed in this original article. Materials and methods It reports on a retrospective study conducted over a five-year period (2018-2023), during which 705 patients aged 18 years and older with a confirmed diagnosis of odontogenic soft tissue abscess of the head and neck underwent emergency surgery. Results The average age of the patients studied was 41 years, with the oldest being an 82-year-old woman. The proportion of males in the study population was higher - 54.18%. Young patients (18-44 years) were the most affected, with a total of 364 patients (213 males and 151 females), while the proportion of old people (75 years of age and older) was the lowest, with a total of 15 patients, including seven males and eight females. The first molars of both jaws (16, 26, 36 and 46) were the cause of the suppurative bacterial infection in the highest number among our study patients - 208 out of 705 (29.5%). Central incisors (teeth 11, 21, 31 and 41) were the least frequent direct cause of odontogenic infection, accounting for only 17 cases out of 705 (2.41%). Discussion The most logical reason for the decrease in the number of patients with odontogenic abscesses with increasing age is tooth loss in older individuals. Our study confirmed the knowledge that the first mandibular molars are the most common teeth leading to the formation of purulent exudate in the adjacent mandibular soft tissues. However, in contrast to the well-known fact for the maxilla that canines are the most frequent etiologic factor for the occurrence of odontogenic abscesses, we conclude that again the first molars (teeth 16 and 26) outnumber the other teeth of the maxillary dentition, with canines outnumbering only incisors. The teeth of the lower jaw are the cause of more than twice as many exudative infections as those of the upper jaw - the ratio between them is 2.54:1. Conclusions Knowledge of odontogenic abscesses - their demographic distribution, frequency and etiology, their diagnosis and treatment - is the basis for the prediction and treatment outcome of these diseases, mainly affecting young people. Their treatment is both surgical in order to evacuate the suppurative focus, and antibacterial.

Evaluation of Cytotoxicity of Allium sativum (Garlic Extract) against Human Dental Pulp Fibroblasts.

Vital pulp therapy procedures in primary dentition focuses on preservation and maintenance of pulp tissue that has been compromised due to caries, trauma, etc. Several pulp dressing materials have been used in primary teeth and some natural materials from the field of traditional medicine have also been introduced as medicaments in vital pulp therapy. The understanding of biologic and cytotoxic properties of newer materials is important for safe clinical usage. The biologic compatibility of these newer materials is imperative to limit or avoid tissue irritation or degeneration. To evaluate the cytotoxic effects of Allium sativum on cultured human primary dental pulp fibroblasts. Primary pulp fibroblasts were cultured from the pulp tissue obtained from extracted deciduous primary canines and central incisor teeth. The freshly prepared concentrations of 1000, 500, 250, 125, and 62.5 µg/mL A. sativum extract were added to the 96-well plate in triplicates to which culture medium containing fourth passage cell suspension was added previously. Cells without treatment served as control, while cells treated with 5% dimethyl sulfoxide (DMSO) served as toxic control. After the addition of experimental and control agents, cells were incubated for 24 and 48 hours at 37°C in 5% CO2 atmosphere. After the incubation period, 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to determine the number of viable cells. Absorbance was read with a microplate reader at 570 nm wavelength and the relative viability of dental pulp fibroblasts at various concentrations was expressed as color intensity of the experimental wells relative to that of control. The percentage of cell viability was also calculated accordingly. The MTT assay results revealed that A. sativum extract, in all the concentrations tested at both the time intervals maintained a cell viability of greater than 90%. At 24 hours, the mean absorbance value of untreated control wells was recorded as 0.84400 ± 0.00916 with 100% cell viability. Among all the concentrations of garlic extract tested, highest mean absorbance value of 0.83933 ± 0.00550 with 99.44% cell viability was recorded for 62.5 µg/mL concentration. At 48 hours, the mean absorbance value of untreated control wells was recorded as 1.22767 ± 0.01106 with 100% cell viability, and the highest mean absorbance value of 1.22567 ± 0.01006 with 99.83% cell viability was recorded for 62.5 µg/mL concentration. The cell viability did not seem to be affected by the concentration of A. sativum extract at 24 hours. However, at 48 hours, the sensitivity of the cells was observed to be dependent on the concentration of A. sativum with a decrease in the viability of cells noted with the increase in concentration. A. sativum extract is noncytotoxic in nature and preserves the vitality of cultured human primary dental pulp fibroblasts making it a suitable material for use in vital pulp therapy procedures of primary teeth. Devaraju R, Reddy D, Paul ST, et al. Evaluation of Cytotoxicity of Allium sativum (Garlic Extract) against Human Dental Pulp Fibroblasts. Int J Clin Pediatr Dent 2024;17(2):143-148.

Bayesian modeling of spatially differentiated multivariate enamel defects of the children’s primary maxillary central incisor teeth

BackgroundThe analysis of dental caries has been a major focus of recent work on modeling dental defect data. While a dental caries focus is of major importance in dental research, the examination of developmental defects which could also contribute at an early stage of dental caries formation, is also of potential interest. This paper proposes a set of methods which address the appearance of different combinations of defects across different tooth regions. In our modeling we assess the linkages between tooth region development and both the type of defect and associations with etiological predictors of the defects which could be influential at different times during the tooth crown development.MethodsWe develop different hierarchical model formulations under the Bayesian paradigm to assess exposures during primary central incisor (PMCI) tooth development and PMCI defects. We evaluate the Bayesian hierarchical models under various simulation scenarios to compare their performance with both simulated dental defect data and real data from a motivating application.ResultsThe proposed model provides inference on identifying a subset of etiological predictors of an individual defect accounting for the correlation between tooth regions and on identifying a subset of etiological predictors for the joint effect of defects. Furthermore, the model provides inference on the correlation between the regions of the teeth as well as between the joint effect of the developmental enamel defects and dental caries. Simulation results show that the proposed model consistently yields steady inferences in identifying etiological biomarkers associated with the outcome of localized developmental enamel defects and dental caries under varying simulation scenarios as deemed by small mean square error (MSE) when comparing the simulation results to real application results.ConclusionWe evaluate the proposed model under varying simulation scenarios to develop a model for multivariate dental defects and dental caries assuming a flexible covariance structure that can handle regional and joint effects. The proposed model shed new light on methods for capturing inclusive predictors in different multivariate joint models under the same covariance structure and provides a natural extension to a nested hierarchical model.

Investigation of the Mesiodistal Angulations of Maxillary Canines and Central Incisors for Missing Bilateral Maxillary Lateral Incisor.

(1) Background: A missing bilateral maxillary lateral incisor (MBMLI) causes aesthetic and functional problems and a multidisciplinary approach is required for treatment. This study aimed to compare the changes in the mesiodistal axial angulations of the maxillary canines and central incisors with orthodontic treatment of MBMLI. (2) Methods: A total of 56 patients with MBMLI were included in the study, and three groups were formed: the control group (Group 1, n = 20) with untreated ideal occlusion and the space opening (Group 2, n = 20) and space closure (Group 3, n = 16) groups as treated study groups. The mesiodistal angulations between the long axes of the maxillary right canine (tooth no 13), right central incisor (tooth no 11), left central incisor (tooth no 21) and maxillary left canine (tooth no 23), and the bicondylar plane, were measured on the panoramic radiographs taken pre (T0) and post treatment (T1). p < 0.05 was accepted for statistical significance. (3) Results: At T0, while there was no significant difference between the mesiodistal angulations of the right-left maxillary canines and central incisors in all groups (p > 0.05), the mesiodistal angulations of the canines in the Group 1 were significantly higher than the study groups (p < 0.05). With treatment, while the mesiodistal angulation of the canines increased in Group 2, it decreased in Group 3 (p < 0.05). On the other hand, the mesiodistal angulation of the central incisors decreased in Group 2 and did not change in Group 3 (p > 0.05). At T1, the mesiodistal angulation of the canines was found to be lower in Group 3 than in Groups 1 and 2, while the angulation of the central incisors was found to be lower in Group 2 compared to Group 1 (p < 0.05). (4) Conclusions: In the orthodontic treatment of MBMLIs, changes in the mesiodistal angulations of the maxillary canine and central incisors should be taken into account for satisfactory outcomes. It was concluded that there should be a tendency to select the space closure method in which normal mesiodistal angulations are obtained in maxillary central incisors for aesthetics and planned incisor position, and also at a low cost.

An in vitro evaluation of Icon resin infiltrant penetration into demineralized enamel lesions using an indirect staining technique with confocal laser scanning microscope analysis in dual fluorescence mode.

White spot lesion is the first clinical sign of a caries lesion and represents mineral loss from the enamel subsurface. The aim of this study was to evaluate the penetration depth (PD) of Icon resin infiltrant into artificially demineralized enamel lesions using confocal laser scanning microscope (CLSM) analysis in dual fluorescence mode. The design of the study was an in vitro study. 22 extracted human permanent maxillary central incisor teeth were collected, and enamel sections were obtained from the coronal middle third. All enamel specimens were exposed to demineralization and remineralization solutions for 14 days. On positive confirmation of enamel demineralization by scanning electron microscope analysis, 20 specimens were then subjected to Icon resin infiltration following manufacturer instructions. Specimens were processed with indirect staining technique using rhodamine B and sodium fluorescein dyes and examined under CLSM at ×10 magnification in dual fluorescence mode using ImageJ software to evaluate PD of resin infiltrant into demineralized enamel lesions. Obtained data were analyzed using an independent t-test. P ≤0.05 was considered statistically significant. The maximum depth of demineralized enamel lesion was 590 μm, and the mean depth was 290.78 ± 14.80 μm. The maximum depth of resin infiltrant penetration was 580 μm, and the mean depth was 279.08 ± 13.88 μm; P = 0.006. The percentage penetration of resin infiltrant was 95.99%. Icon resin infiltrant was highly effective in its depth of penetration into demineralized enamel lesions. The use of indirect staining and CLSM analysis in dual fluorescence mode is more reliable and accurate technique to evaluate the PD of resin infiltrant.

Evaluation of Radicular Dentin Thickness in Maxillary and Mandibular Central Incisor, Canine, and Premolar Teeth.

Background This study aimed to compare the radicular dentin thickness in single-rooted maxillary and mandibular anterior and premolar teeth by measuring on four different surfaces (buccal, lingual, mesial, and distal) at three different levels (apical, middle, and coronal). Methods A total of 150 single-rooted human anterior and premolar teeth were included in the present study. The teeth were sectioned at the cemento-enamel junction (CEJ; coronal), 4 mm away from the apex (apical), and the midpoint between these two distances (middle).First, the teeth were divided buccolingually into two parts, and the dentin thickness in the mesial/distal region was measured. Subsequently, both parts were divided again to measure the dentin thickness in the buccal/lingual region. All measurements were recorded, and statistical analysis was performed. Results Apical radicular dentin thickness was significantly less than CEJ (p < 0.001). The maxillary central incisor, maxillary, and mandibular canine exhibited the maximum radicular dentin thickness, whereas the mandibular premolars showed the minimum. Radicular dentin thicknesses on the lingual and buccal surfaces were significantly higher than those on other surfaces (p < 0.001). Conclusion The lowest radicular dentin thickness values were observed in the premolars, especially on mesial and distal surfaces. Considering these areas as danger zones and paying attention during dental procedures are essential to avoid possible complications.

Effect of attachment configuration and trim line design on the force system of orthodontic aligners: A finite element study on the upper central incisor.

To use the finite element method (FEM) to investigate the effect of various attachment configurations and trimming line designs of orthodontic aligners on their biomechanical performance. A 3D upper jaw model was imported into 3D design software. The upper right central incisor tooth (Tooth 11) was made mobile, and its periodontal ligament (PDL) and bone structures were designed. Aligners were modelled with three distinct attachment configurations: No attachment, rectangular horizontal, rectangular vertical, and two trimming line designs; scalloped and straight extended, with a homogeneous thickness of 0.6 mm. These models were then imported into an FE software. Simulations were conducted for three different movements, including facial translation, distalization, and extrusion. Forces were recorded at 1.3-2.6 N during facial translation, 1.4-5.9 N in distalization, and 0.0-2.0 N in extrusion. The straight extended trimming line consistently generated higher forces than the scalloped design. Attachments had no significant impact on force components during facial translation but were more effective in distalization and extrusion. The combination of a straight extended trimming line with horizontal attachments exhibited the least stresses at the apical third during distalization, and the highest stresses during extrusion, suggesting superior retention. Rectangular attachments offer limited benefits in facial translation, but horizontal rectangular attachments can intensify load in distalization and are crucial for force generation in extrusion. Horizontal attachments are preferred over vertical options. Additionally, the straight extended trim line enhances control of tooth movement and can replace attachments in certain cases. These findings provide biomechanical evidence and an optimal protocol to guide clinical practice in planning diverse teeth movements. The emphasis is on the influence of attachment utilization and the specific design of aligner trimming lines to enhance control over tooth movement.